diff options
Diffstat (limited to 'arch/i386/kernel/e820.c')
| -rw-r--r-- | arch/i386/kernel/e820.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/arch/i386/kernel/e820.c b/arch/i386/kernel/e820.c index 47c495bf0cb..b755255f272 100644 --- a/arch/i386/kernel/e820.c +++ b/arch/i386/kernel/e820.c @@ -33,6 +33,7 @@ unsigned long pci_mem_start = 0x10000000; #ifdef CONFIG_PCI EXPORT_SYMBOL(pci_mem_start); #endif +extern int user_defined_memmap; struct resource data_resource = { .name = "Kernel data", .start = 0, @@ -706,3 +707,154 @@ void __init register_memory(void) printk("Allocating PCI resources starting at %08lx (gap: %08lx:%08lx)\n", pci_mem_start, gapstart, gapsize); } + +void __init print_memory_map(char *who) +{ + int i; + + for (i = 0; i < e820.nr_map; i++) { + printk(" %s: %016Lx - %016Lx ", who, + e820.map[i].addr, + e820.map[i].addr + e820.map[i].size); + switch (e820.map[i].type) { + case E820_RAM: printk("(usable)\n"); + break; + case E820_RESERVED: + printk("(reserved)\n"); + break; + case E820_ACPI: + printk("(ACPI data)\n"); + break; + case E820_NVS: + printk("(ACPI NVS)\n"); + break; + default: printk("type %lu\n", e820.map[i].type); + break; + } + } +} + +void __init limit_regions(unsigned long long size) +{ + unsigned long long current_addr = 0; + int i; + + print_memory_map("limit_regions start"); + if (efi_enabled) { + efi_memory_desc_t *md; + void *p; + + for (p = memmap.map, i = 0; p < memmap.map_end; + p += memmap.desc_size, i++) { + md = p; + current_addr = md->phys_addr + (md->num_pages << 12); + if (md->type == EFI_CONVENTIONAL_MEMORY) { + if (current_addr >= size) { + md->num_pages -= + (((current_addr-size) + PAGE_SIZE-1) >> PAGE_SHIFT); + memmap.nr_map = i + 1; + return; + } + } + } + } + for (i = 0; i < e820.nr_map; i++) { + current_addr = e820.map[i].addr + e820.map[i].size; + if (current_addr < size) + continue; + + if (e820.map[i].type != E820_RAM) + continue; + + if (e820.map[i].addr >= size) { + /* + * This region starts past the end of the + * requested size, skip it completely. + */ + e820.nr_map = i; + } else { + e820.nr_map = i + 1; + e820.map[i].size -= current_addr - size; + } + print_memory_map("limit_regions endfor"); + return; + } + print_memory_map("limit_regions endfunc"); +} + + /* + * This function checks if the entire range <start,end> is mapped with type. + * + * Note: this function only works correct if the e820 table is sorted and + * not-overlapping, which is the case + */ +int __init +e820_all_mapped(unsigned long s, unsigned long e, unsigned type) +{ + u64 start = s; + u64 end = e; + int i; + for (i = 0; i < e820.nr_map; i++) { + struct e820entry *ei = &e820.map[i]; + if (type && ei->type != type) + continue; + /* is the region (part) in overlap with the current region ?*/ + if (ei->addr >= end || ei->addr + ei->size <= start) + continue; + /* if the region is at the beginning of <start,end> we move + * start to the end of the region since it's ok until there + */ + if (ei->addr <= start) + start = ei->addr + ei->size; + /* if start is now at or beyond end, we're done, full + * coverage */ + if (start >= end) + return 1; /* we're done */ + } + return 0; +} + +static int __init parse_memmap(char *arg) +{ + if (!arg) + return -EINVAL; + + if (strcmp(arg, "exactmap") == 0) { +#ifdef CONFIG_CRASH_DUMP + /* If we are doing a crash dump, we + * still need to know the real mem + * size before original memory map is + * reset. + */ + find_max_pfn(); + saved_max_pfn = max_pfn; +#endif + e820.nr_map = 0; + user_defined_memmap = 1; + } else { + /* If the user specifies memory size, we + * limit the BIOS-provided memory map to + * that size. exactmap can be used to specify + * the exact map. mem=number can be used to + * trim the existing memory map. + */ + unsigned long long start_at, mem_size; + + mem_size = memparse(arg, &arg); + if (*arg == '@') { + start_at = memparse(arg+1, &arg); + add_memory_region(start_at, mem_size, E820_RAM); + } else if (*arg == '#') { + start_at = memparse(arg+1, &arg); + add_memory_region(start_at, mem_size, E820_ACPI); + } else if (*arg == '$') { + start_at = memparse(arg+1, &arg); + add_memory_region(start_at, mem_size, E820_RESERVED); + } else { + limit_regions(mem_size); + user_defined_memmap = 1; + } + } + return 0; +} +early_param("memmap", parse_memmap); |